gms | German Medical Science

7th EFSMA – European Congress of Sports Medicine, 3rd Central European Congress of Physical Medicine and Rehabilitation, Annual Assembly of the German and the Austrian Society of Physical Medicine and Rehabilitation

Outline

Objective: Many children and adolescents practice high performance sport in a club or a training center. Medical examination before and all along the training are mandatory and useful for good practice of sport. Cardio-respiratory test during exercise is one major component of this evaluation. Test protocols are well defined and based in our laboratory on theoretical values of VO2max that were defined in the eighties, by tests performed on a population of young North American adolescents for whom there are limited information on their daily workload [1]. Our objective was to assess the relevance of these reference values during the evaluation of young athletes registered in the training center (CREPS) of Strasbourg.

Material/Methods: This retrospective study involved 266 athletes covering 27 different sports, according to the Mitchell classification [2]. 161 boys and 105 girls, between 9 and 17 years old, were all listed either in a training center or as high performance athletes in Alsace. They have all performed a maximal exercise test up to exhaustion, on an ergocycle, in order to determine their VO2max and their ventilatory threshold.

Results: For the whole group of 266 children, the maximal measured O2 uptake (VO2max ) averages 2.87+/- 0.87 L.min-1, i.e. 113 +/-19% of predicted values. Boys have a mean VO2max of 3.32 +/- 0.75 L.min-1 (51 +/- 8 mL.min-1.kg-1), i.e. 108 +/-17% of predicted values and the girls have a mean VO2max of 2.17 +/- 0.52 L.min-1 (41 +/- 7 mL.min-1.kg-1), i.e. 120 +/-19% of theoretical values. VO2max significantly increases with age (p<0.001) but remains stable when expressed with weight (specific VO2 max). For both girls and boys, the ventilatory threshold is relatively high and averages 64 +/- 9% of VO2max. The highest values of VO2max are observed in the C group of the Mitchell’s classification, whatever the sex. To characterize the difference between both predicted and measured VO2max, we used the Bland-Altman’s method. For the boys, it shows that the mean of measured VO2max is 210 +/- 530 ml higher than the mean predicted VO2max value (Figure 1 [Fig.Â 1]). For the girls, the difference reached 360+/- 360 ml (Figure 2 [Fig.Â 2]). In both groups, these differences are not statistically significant.

Conclusion: The measured VO2max of adolescents listed as potentially high performance athletes are higher than the values derived from the Cooper and coll. [1] formulae, but the difference is not clinically significant, neither for boys and girls. For this specific population, we can assume that the values of VO2max calculated with Cooper’s formulae can still be used as predicted values, between 9 and 17 years old.